Thermoformable multi-part slipper

ABSTRACT

A device for fitting onto a foot and ankle of a human body which is a thermoformable element suitable for being thermoformed onto the foot. This element includes a first part and a second part which are joined together in an edge-edge relationship. Each of the first and second parts is formed of a sheet of thermoformable material. The sheet of the first part has a different thickness or density than the sheet of the second part. The first part extends over the foot and the second extends around the ankle. A third part can be joined in edge-to-edge relationship to the first and second parts and extends over the top of the foot.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to components that are intended to fit aportion of the body for the purpose of increasing the comfort of thatportion of the body or for carrying out a prosthetic function, such assupporting or holding organs that have been displaced by accident andsubstituted by artificial mechanisms. The present invention relates tosuch components that can be thermoformed on the body or on a rigidthermoforming structure. The present invention also relates to suchcomponents that can be used as footwear designed to ensure a calculatedsupport of the foot and to be worn within a generally rigid shoe.

2. Description of Related Art

Known slippers to be made to fit the foot of the user. If necessary,such slippers can undergo a second thermoforming in a rigid shell formedby the shoe into which the slipper is inserted.

French Patent No. 94.10939 describes a slipper that consists of a partdesigned to receive the foot and a part that is roughly tubular so as tosurround the bottom of the leg. This slipper also contains flaps. Thisslipper is made of a comfortable material between the foot and the shoeso that it conforms to the foot of the user. In this prior art patent,this comfortable material is made of a thermoplastic and/orthermoformable material that is made malleable by heating.

International Patent Application No. WO 94/09663 also describes aslipper of the same type. This slipper is made of a single piece with anaxial seam. The slipper is equipped, at the joint of the ankle and thetibia, with flaps that fold onto each other. This slipper is also madeof a thermoformable material that is able to be formed at a temperaturethat the user can tolerate. The technique of this item of prior artmakes it possible to obtain a formable shape which allows for theadjustment of the foot in the shoe in order to obtain precisepositioning of objects fixed to the shoe, such as a ski.

When in use, these known slippers are not properly designed. Inparticular, notably in the case of ski boots, the internal dimensions ofthe rigid shell are such that it is as close as possible to shape of thefoot. It is necessary that the slipper conforms both the form of thefoot and to that of the shell and that both a correct tightening of theankle/tibia joint be obtained. Another problem of the slippers of theprior art is that are made of a single piece (as described inInternational Patent Application No. WO 94/09663) or of two pieces (asdescribed in French Patent No. 2 724 295). If they obtain a propertightening around the ankle-tibia joint, there is little space for thefoot. As a result, the foot is not able to spread out properly. Inaddition, the covering of the instep or the portion in front of theankle-tibia articulation zone is done with overlapping flaps. Thiscreates an excessive thickness that generates a pressure on the foot. Asa result, the shoe will fit uncomfortably.

The examples of the problems of the prior art in the field of making theslippers are common to all scenarios involving the use of thermoformablematerials utilized in prosthetic applications.

BRIEF SUMMARY OF THE INVENTION

The present invention is intended to overcome the disadvantages of theprior art by creating a slipper having waterproof seams and which allowsa proper tightening of the foot within the shoe while also allowing aspreading of the foot and a tightening in the area of the joint of theankles and the tibia. The present invention creates a prosthetic orcomfortable component for the body made of several assembled parts whichare waterproof at the junctions of the parts. These parts do not haveexcessive thickness at these junctions. The parts have differentthicknesses or densities.

The present invention is a component designed to fit a portion of thebody for the purpose of increasing the comfort of that portion of thebody or for carrying out a prosthetic function of supporting or holdingorgans that have been replaced by artificial mechanisms. This componentcan be thermoformed on the body or in a shell that contains thecomponent. The component is made from materials of cut sheets which arethermoformable at a temperature suitable to the body. The component ischaracterized in that it is made of at least two cut and assembledparts. The sheets that form the thermoformable material of the first andsecond parts have different thicknesses or different densities.

The parts of the component of the present invention are assembled bygluing, bonding or sewing. The parts are joined in edge-to-edgerelationship to each other. The edge of the part having the greaterthickness is fitted to adjust the thickness of the part of lesserthickness.

The first part surrounds the foot so as to be closed under the sole ofthe foot. The second part surrounds the ankle and is mounted to thefirst part. The first part has a lesser thickness than the second part.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

FIG. 1 is an exploded view of the parts that form the slipper accordingto the present invention.

FIG. 2 is a view of the component that forms the obturating tongue.

FIG. 3A is a view of the front of the slipper assembled prior tothermoforming.

FIG. 3B is a view of the side of the slipper assembled prior tothermoforming.

FIGS. 4-6 represent, in a schematic manner, the assembly of the piecesthat form the slipper of the present invention.

FIG. 7 is a side view of the thermoformed slipper.

FIG. 8 shows a component in accordance with the present invention thatis made of footwear having a sole.

DETAILED DESCRIPTION OF THE INVENTION

The component according to the present invention is of a type designedto fit a portion of the body for the purpose of increasing the comfortof that portion of the body. The present invention can be a slipper,either for walking with a sole, or designed to be worn within a shoe.

The component according to the present invention can also be designed tocarry out a prosthetic function for supporting or holding organs thathave been replaced by artificial mechanisms, for example, a slipperdesigned to support the sole of the foot in the arch of the foot ordesigned to adjust the position of the toes. The prosthetic device canbe a pin, a ball and a socket joint, a corset, a surgical collar, asplint for supporting the leg, or any other component used forprosthetic function in humans or animals. The component can be made of asheet material that can be cut, sewn, glued, or bonded.

The component according to the present invention can be placed in ashell or cup. The component is made from sheet materials that can becut, glued, sewn or bonded. The material of the component of the presentinvention can be thermoformed onto the body or formed within a shellthat contains the material. For example, a first thermoforming can bemade onto the body or onto a structure that reproduces that component ofthe body. A second thermoforming can be carried out in a shell.

The attached drawings of FIGS. 1-7 represent a component that forms aslipper designed to be worn within a shoe. This slipper is made of asheet material that can be cut and sewn. The material can also be gluedor bonded with heat by localized melting. The material is thermoformableat a temperature that can be tolerated by the user and thus suited tothe human body. The temperature of thermoforming is relatively low. Theslipper according to the present invention is designed to be worn withina sport shoe or a shoe having a soft shell, a semi-rigid shell, or arigid shell, such as ski boots.

The thermoformable slipper according to the present invention is made ofa first part 1. This first part 1 is shown in FIG. 1 in a flattenedconfiguration. The first part 1 is closed along its longitudinal axiscorresponding to the sole of the foot at the junction of the two loweredges 2. The first part 1 will surround the foot. The slipper alsoincludes at least one second part 3 which is affixed along the upperedge 4 of part 1.

In FIG. 1, parts 1 and 3 are illustrated in a flattened condition. Part3 surrounds the ankle and the area of the joint of the ankle and thetibia. Part 3 has a shape that is roughly tubular after it is positionedso as to conform around the angle and the tibia. Part 3 includes afrontal part or a front portion above the instep of the foot. Part 3 caninclude flaps that fold on each other so as to ensure closing andwaterproofing.

The slipper has a part 5 which has a front portion in the shape of atriangular area 5A, as illustrated in FIG. 2. Part 5 is affixed to part1 on the upper of the slipper in order to cover the top of the foot andextend toward the rear into an open portion 5B forming the obturatingtongue. This obturating tongue is located between the vertical edges ofthe tubular part 3, as illustrated in FIG. 3. The top of the triangulararea 5A can also be rounded.

In the present invention, the cut thermoformable sheet materials thatare used to make the first part surrounding the foot and the second partsurrounding the ankle of either totally or partially different thicknessor densities or also having different flexibilities and rigidities.Preferably, part 2 is thicker than part 1. Because part 1 is less thick,it allows for more space within the shoe so as to allow a comfortablespreading of the foot. Since part 1 is less thick, it also remains moreflexible after thermoforming. Part 3 is more rigid than part 2 so as toensure a proper support of the ankle. Part 2, in the preferredembodiment of the present invention, has a thickness of 10 millimeterswhile the part 1 will have a thickness of approximately 5 millimeters.Part 2 has a greater density than either part 1 or part 3.

The component according to the present invention is made of at least twoparts. The sheets that form these parts have different thicknesses ordensities. The component of the present invention is made of N partsassembled in a manner in that at least one of the N parts has a sheetwith a thickness or density different than the others. The sheet cancorrespond to the part which holds the organs that have been replaced byartificial mechanisms.

In the preferred embodiment of the present invention, part 5 is made ofa thermoformable sheet material having the same thickness as part 3which surrounds the ankle. However, within the present invention, it ispossible that part 5 is thicker than part 1 and can be of a differentthickness than either part 1 or part 3. Also, in accordance with analternative embodiment of the present invention, the sheet material usedfor the parts 1, 3 and 5 can be thicker for part 3 which is the top ofthe shoe, and for part 5. In another embodiment of the presentinvention, part 1 can be thicker than the upper part 3 which surroundsthe ankle.

The assembly of the parts can be carried out by sewing the parts in edgeto edge relationship, as shown in FIGS. 4-6. In FIG. 4, sheet 6corresponds to one of the parts of lesser thickness, such as part 1.Sheet 7 shows a sheet corresponding to the part having greaterthickness, such as either part 3 or part 5. During the sewing of thesheets 6 and 7 in edge-to-edge relationship, the difference in thethicknesses can create an area which is uncomfortable for the user.

In the present invention, the part is fitted, along its cut edge, so asto adjust the thickness over the part having lesser thickness. Thisadaptation, as shown in FIGS. 4-6, is obtained by creating an engravedgroove 8 along the cut edge of the sheet so as to form two paralleltongues 9. During the assembly, the groove 8 is filled with glue. Asshown in FIG. 5, the tongues 9 are brought together so as to close thegroove 8. As a result, the cut edge of sheet 7 will be roughly the samethickness as the sheet 6. The sheets 6 and 7 are thus joined, as shownin FIG. 6, in edge-to-edge relationship along their glued section by theglue which coats the tongues 9 and is contained within the groove 8.These edges can be suitably sewn, as shown in FIG. 6. This allows aproper assembly of the parts without an excess thickness area. Thismanner of assembly also makes the present invention more watertight.

This same type of assembly can be carried out when the slipper isequipped with one piece 5, as shown in FIG. 2, which is sewn by thesides 10 at portion 5A and which is of a larger thickness than the sheetforming part 2. The glue can be replaced by edge-to-edge bonding withlocalized heating. The adaptation of the cut edges of the sheets for theassembly can be carried out in a different manner than stated above. Forexample, it is possible to compress the material that is thickest beyondits limit of elasticity by heating. As such, it will have the samethickness as that of narrower sheet of material. It is also possible tomachine or abrade the sheet so as to reduce the thickness.

FIG. 8 shows the footwear having a sole 11 assembled in a traditionalmanner with an upper 12 and a rear part 13. The upper 12 and the rearpart 13 are either of a different thickness, or of a different densitydepending on the type of prosthetic function that would be assigned tothem. At least one of the parts can be made of a non-thermoformablematerial.

I claim:
 1. A device for fitting onto a tibia and an ankle and a foot ofa human body comprising: a thermoformable element comprising a firstpart means for surrounding a portion of the foot and a second part meanssuitable for surrounding a portion of the ankle and the tibia, saidsecond part means having a greater thickness than said first part means,said second part means having an edge with a groove formed between twotongues, each of said two tongues having an edge facing an edge of saidfirst part means, the edges of said two tongues being juxtaposed againsteach other and joined to said edge of said first part means such that aninner surface and an outer surface of said first part means adjacent theedge thereof being flush with an inner surface and an outer surfacerespective of said second part means adjacent the edge thereof, a totalthickness of said two tongues having a thickness equal to a thickness ofsaid first part means at the edge thereof.
 2. The device of claim 1,further comprising a third part formed of a sheet of nondeformablematerial, said third part being joined in edge-to-edge relationship toat least one of said first and second part means.
 3. The device of claim2, said third part having a thickness equal to a thickness of saidsecond part means.
 4. The device of claim 1, said first part means forsurrounding the foot and for being closed below the foot, the devicefurther comprising: a third part means for covering a top of the foot,said third part means being joined in edge-to-edge relationship to eachof said first and second part means.
 5. The device of claim 1, said twotongues being glued together.
 6. The device of claim 1, said groovebeing filled with glue.
 7. The device of claim 1, the edges of saidsecond part means being secured to the edge of said first part means. 8.The device of claim 1, the edges of said second part means being boundto the edge of said first part means.
 9. The device of claim 1, saidfirst and second part means for thermoforming on the foot and the ankleof the human body.